Currently, dual-screen smartphones draw increasing attention. There are mainly two types of dual-screen mobile phones:
One type is a clamshell dual-screen mobile phone shown in FIG. 1, and screens are respectively disposed on the inside and the outside of a clamshell part. When the clamshell part is closed, a screen on the outside is lighted if a user triggers a screen lighting operation; or when the clamshell part is open, a screen on the inside is lighted.
The other type is a bar dual-screen mobile phone shown in FIG. 2, and screens are respectively disposed on a front side and a back side of the mobile phone. Usually, a color screen is disposed on the front side of the mobile phone, and a color screen or an ink screen, usually the ink screen, is disposed on the back side of the mobile phone.
In the bar dual-screen mobile phone, a switching button that can be tapped by a user is provided in a mobile phone interface to perform a switching operation between two screens. When a front screen of the mobile phone is in a screen-on state, a switching button on the front screen is tapped to switch to a back screen, so that the back screen is in the screen-on state for use; and the front screen is turned off to save power. When a back screen of the mobile phone is in a screen-on state, a switching button on the back screen is tapped to switch to a front screen, so that the front screen is in the screen-on state for use; and the back screen may be turned off, or may not be turned off. If the back screen is not turned off, no event can be triggered by touching the back screen.
For the bar dual-screen mobile phone, when both screens are in a screen-off state, when the user triggers lighting of a screen through a specific operation (for example, pressing a power button, pressing a Home button or a voice control button, or another operation), the user may detect a screen in an upward direction by using an acceleration sensor (or referred to as a gravity sensor) in the mobile phone. As shown in FIG. 3(a), a front color screen is lighted if it is detected that the front color screen is in the upward direction. As shown in FIG. 3(b), a back ink screen is lighted if it is detected that the back ink screen is in the upward direction.
However, in some special scenarios, for example, when the user lies on a back or a side of the user, it is determined based on a detection result of the acceleration sensor that a lighted screen is not a screen that the user expects the mobile phone to light. The user needs to perform a plurality of operations by using the switching button, to light the screen that the user expects the mobile phone to light. Consequently, user experience is relatively poor.